The present invention relates to 4-heterocyclic-4-[N-(phenyl)amido]piperidine derivatives and methods and compositions employing such compounds and methods of preparing the same. In particular, this new class of compounds has been found to possess desirable analgesic and anesthetic properties.
A number of patents disclose certain N-phenyl-N-(4-piperidinyl) amides having analgesic activity. For example, some such compounds are disclosed in U.S. Pat. Nos. 3,164,600 and 3,998,834. U.S. Pat. No. 3,164,600 discloses such compounds in which the 4 position of the piperidine ring is substituted by a lower alkyl.
According to the report of S. McElvain et al., JACS, Vol. 80 (1958), changes in the 4-position of certain substituted piperidines generally lead to less or no analgesic activity. For example, McElvain et al. teaches that in going from methyl to butyl, there is no apparent effect on the degree of analgesia, and the 4-phenyl substituent fails to produce any marked effect.